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The Earth is warming. Determining what this will mean for future
generations is one of the greatest challenges in modern science,
and UNCW Environmental Science Studies Professor Paul Hearty has
been tapped as one of a world-class team of scientists working to
provide answers to this question.

Hearty is one of five principal investigators on a grant to
build a comprehensive model of past climate change by integrating
elements of the world's crust, oceans, atmosphere and ice sheets,
using fossil and geological data from an ancient warming period 3
million years ago. The National Science Foundation has funded the
five-year study for $4.25 million, a rare achievement in an age
when basic research budgets have been drastically cut and many
studies are funded.

Approximately 3 million years ago, the Earth was warmer. Global
average temperatures were 2-3 Celsius (3.6F to 5.4F) greater than
today. Known as the Mid-Pliocene Climatic Optimum (PLIOMAX), this
interval has received renewed attention by researchers because its
temperatures and composition of the atmosphere are similar to those
predicted by global climate change models of the coming
century.

"We have to go back 3 million years to find CO2
levels of 400 ppm. Our atmosphere, now at about 393 ppm, will
easily reach 400 ppm by the end of this decade." said Hearty.

Over the next five years of the grant, the PLIOMAX team will
tackle three major problems in climate science. In the first phase,
they intend to use fossil and geological data collected at sites
across the world to build a greatly improved database of sea levels
and thus ice sheet behavior during the Pliocene.

"Geology has to drive this process. Geology provides first-hand
information about the position and movements of sea level," said
Hearty.

In a subsequent phase of the project, these data will feed into
a series of experiments that will provide estimates of the global
sea level under a variety of climate change scenarios. From
this work, the team also intends to build a high-resolution
comprehensive model of the world's atmosphere-ocean-ice sheet/shelf
systems. The ultimate goal of the project is to better forecast the
potential behavior of sea-level and ice sheets in a warmer
world.

For climate researchers, the Mid-Pliocene represents the last
great warm period in Earth's history. As the era's climate roughly
resembles the late 21st century projected by the UN's
Intergovernmental Panel on Climate Change, the Pliocene has drawn
extensive academic interest in recent years. Agencies such as the
U.S. Geological Service and the British Geological Survey have
begun major efforts to construct data models from this period.

While there is general agreement about the temperatures of the
Pliocene,, controversy exists about the extent to which these
warmer temperatures and higher carbon dioxide levels affected
global sea levels. Researchers agree that sea levels were higher
during the Mid-Pliocene, but the magnitude of the rise has been
hotly debated. Researchers' estimates have ranged from 10 meters
(32 ft.) to around 40 m. (131 ft.) higher than today. Higher sea
levels are directly tied to melting of the world's polar ice sheets
such as Greenland and Antarctica.

Hearty is hesitant to make predictions based on the past. He
acknowledges the complexities of predicting the future through
studying geological and modeling data. Climate science deals with a
massively complex system, and the variables that led to sea level
rise 3 million years ago included more than simple temperature and
CO2 relationships.

Even so, the most conservative estimates of sea level rise
during the period would, if repeated in a warming future,
dramatically change the shape of the world's coastlines. On a
geological scale, measured in millions of years, the ocean has
risen and fallen many times due to climate change. Hearty said
important geological evidence of this can be found throughout
Southeastern North Carolina, which once was submerged beneath the
ocean.

Hearty will serve as one of the principal investigators on the
grant, a prestigious spot on a project featuring an all-star team
of researchers from the top universities in the United States. The
project's leader, Professor Maureen Raymo of Columbia University,
is widely recognized as a global leader in the field of
paleoclimatology and paleoceanography. She and the other members of
the team have, working jointly in various combinations, have
published widely on climate change in the Pliocene.

Hearty has worked and published with the team for years,
including leading a field expedition in Australia from which
findings provided the rationale for the larger study. Raymo praises
Hearty's fieldwork skills, calling him one of the best in the world
at interpreting sea level changes from the rocks and analyzing
fossil data.

"Paul is an amazing field geologist with decades of experience
looking at the coastal record of sea level change. I call
him 'The Rock Whisperer,'" said Raymo.

The grant's other principal investigators - geoscientist Rob
DeConto from the University of Massachusetts-Amherst, physicist
Jerry Mitrovica of Harvard and earth scientist David Pollard of
Penn State - all have world-class reputations in their fields. In
recommending the grant for full funding, the reviewers at the
National Science Foundation cited the vast expertise of the team as
a major factor in the decision.

Hearty's role will be to lead field expeditions collecting the
fossil and geological evidence that will make up the raw data to be
used by the ice and crustal modelers. One of the chief hurdles in
accurately modeling the past and future behavior of global climate
has been a lack of sea-level data.

The PLIOMAX team has already provided solutions to some of the
period's greater mysteries. In examining past glaciations and
interglacials, they determined that not only will the levels of the
oceans rise when the ice melts, but the earth itself will actually
slowly respond when relieved of the pressure of millions of tons of
ice. The deformation of the earth combined with the rising waters
has led to some of the large discrepancies in findings of past
studies.

"You can load kilometers of ice on a continent, and as the ice
disappears, the continent rebounds hundreds of meters," said
Hearty.

Resolving this controversy is of more than academic interest.
The world's governments will need accurate projections to plan for
a world of rising seas. In recommending that the study receive full
funding, the NSF's review panel praised the research's strong
societal relevance.

To collect this data, Hearty and other members of the PLIOMAX
team gather samples and precise measurements from regions that
share common traits: coastal regions located in tectonically stable
areas far from tectonic plate boundaries. The team has already
gathered data in Australia, will travel to South Africa this year
and plan with planned research expeditions to India, Madagascar and
throughout the Southeastern United States..

Much of this research would have been impossible little more
than a decade ago, because of the vast amounts of manpower and time
that it would have taken to collect the data. With tools like
differential GPS units that are topographically accurate within a
few centimeters and Google Earth images, the team can accomplish in
a single day research that would have taken researchers much longer
in past years.

"Armed with a laptop and a GPS on your dashboard in real time
you can track yourself and potential outcrops on a digital geologic
map" said Hearty.

Hearty trusts the final results of the study will prove valuable
in the future.. By understanding the response of nature to past
global changes, he hopes that future generations will be better
prepared to deal with the anticipated effects of climate and
sea-level changes.

"None of us think that in our human lifetime or even over
several generations, sea level is going to rise 25 meters," said
Hearty.

But it will rise. It has in the past, and it will again in the
future. Hearty says that addressing these changes will be one of
the major challenges of the world's future leaders.

"We're tinkering with a natural machine we don't understand,"
said Hearty.

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